1. Field of the Invention
The present invention relates to a packaging structure for an ink tank and an ink tank packaged in such packaging structure, and especially a packaging structure for an operator-changeable ink tank to be used in the form of coupling to an ink-jet head or an intermediate connecting member and an ink tank packaged in such packaging structure.
2. Description of Related Art
In most cases, an operator-changeable ink tank, which is to be used in the form of coupling to an ink-jet head or an intermediate connecting member, comprises two different openings: an ink supply port for supplying ink to the ink-jet head and an atmosphere communicating port for introducing air commensurate in volume with ink consumption.
For avoiding contamination of the ink tank, its user's hands, or the like with an ink leak, a requirement for the ink tank having such two different openings is to prevent leakage of ink therefrom at a physical distribution with reliability and to prevent leakage of ink therefrom at the time of opening a sealed package reliably for replacing the ink tank with new one.
One of the previous attempts to fill the requirement, as disclosed in Japanese Patent Application Laid-open No. 76367/1995, is to provide a packaging member that comprises: an ink cartridge for retaining ink therein and having an opening portion for supplying ink to the outside; and a packaging member for packaging the ink cartridge, in which at least one end of a seal member for sealing the opening portion of the ink cartridge is anchored to an inner surface portion of the packaging member. In that reference, furthermore, a method for opening the sealed package is also disclosed. The method includes the step of tearing a part of the packaging that corresponds to a non-sealed portion of the ink cartridge by utilizing the packaging member itself to bare a part of the ink cartridge and stripping the seal member from the ink cartridge as a result of pulling the ink cartridge out of the packaging member.
For an ink cartridge having two different openings: an ink supply port and an atmosphere communicating port, it has been suggested that a seal member for sealing the openings is shaped so as to have a portion thereof in close proximity to a portion for sealing the ink supply port and the former portion is responsible for reducing peel force to be generated by stripping the seal member from the ink cartridge to open the atmosphere communicating port at fast to prevent an ink leak to be caused by increasing an inner pressure of the ink cartridge at the time of opening the package.
Considering the packaging member and its opening method disclosed in the above Japanese Patent Application Laid-open No. 76367/1995, by the way, it is possible to avoid an ink leak in physical distribution because a part of the packaging that corresponds to a non-sealed portion of the ink tank can be torn by utilizing the packaging member itself to bare a part of the ink tank and the seal member is pulled from the ink tank as a result of pulling the ink tank out of the packaging member. In this case, however, there is no guarantee that the atmosphere communicating port can be opened at fast, resulting in the reliability being insufficient.
Furthermore, a seal member having a portion for reducing a peel force in close proximity to the portion for sealing an ink supply port is only effective on a usage pattern that a single seal member seals upon the ink supply port and an atmosphere communicating port together. Therefore, the range of uses of the seal member is limited to a particular configuration of the ink tank.